AB1475 DOES VEIN WALL THICKNESS HAVE PROGNOSTIC VALUE IN BEHÇET’S DISEASE? A PROSPECTIVE FOLLOW-UP STUDY
Authors: K. Abacar, R. Ergelen, F. Temiz, Y. Yildiz, T. Ergun, H. Direskeneli, F. Alibaz-Oner
Journal: Annals of the Rheumatic Diseases (2023)

<h3>Background</h3> We reported the first controlled doppler ultrasound study showing increased common femoral vein (CFV) thickness in Behçet's Disease (BD).<sup>[1]</sup> We also recently showed that increased CFV thickness is a distinctive feature of BD, rarely present in other inflammatory or vascular diseases with a specificity higher than 80% for the cut-off value of ≥ 0.5 mm.<sup>2</sup> However, the association between CFV thickness and any organ involvement, disease course or treatment during disease course has not been demonstrated so far. <h3>Objectives</h3> This study aimed to assess the longitudinal course and prognostic value of CFV thickness measurement during a prospective follow-up BD patients. <h3>Methods</h3> In this study, we included 195 patients with a diagnosis of BD. The clinical, demographic, treatment data and biomarkers were recorded during routine visits. Bilateral CFV thickness was measured with ultrasonography by an experienced radiologist at the same day. Patients were started to follow up prospectively with 3-6 months intervals and in any urgent visit. <h3>Results</h3> At baseline, 98.6% of patients had increased CFV wall thickness above the cut-off value of ≥0.5 mm. The baseline and last follow-up clinical characteristics were shown in Table 1. 139 of 195 patients had prospective clinical follow-up data with a mean of 26.5 (16.9) months. New major organ involvement or relapse leading to treatment change was seen in 39 (28%) patients. Among 22 (15.8%) patients with new major organ involvement, 12 had vascular, seven had ocular, two had neurologic and one had gastrointestinal involvement. Among 36 patients with only mucocutaneous disease at baseline, new major organ involvement developed in 9 patients during follow-up. These nine patients had higher baseline CFV thicknesses compared to patients without major organ involvement, however without reaching clinical significance (0.83 mm vs 0.73 mm for right CFV, 0.80 mm vs 0.73 mm for left CFV: p &gt;0.05 for both) In 47 patients, the second CFV thickness measurement was done with a mean 19.8 months after the first visit. There was no statistically significant difference between the first and second CFV wall thickness measurements for both right and left CFVs (First vs. second for right CFV: 0.79 vs. 0.76 mm, p=0.26; for left CFV: 0.79 vs. 0.75 mm, p=0.26). We did not find any change in CFV wall thickness with the treatment modality, new organ involvement and relapses. <h3>Conclusion</h3> CFV wall thickness measurement with ultrasonography which is a new non-invasive diagnostic tool for BD, does not show a major change over time with treatment modality, new organ involvement or disease relapses. However, our preliminary results suggest that mucocutaneous BD patients with higher CFV thickness may have a higher risk for the development of major organ involvement during follow-up. The long term results of our prospective cohort with increased patient numbers would clarify the prognostic value of CFV thickness in BD. <h3>Disclosures</h3> None. <h3>References</h3> [1]Alibaz-Oner F Clin Rheumatol 2019 [2]Alibaz-Oner F. Rheumatology (Oxford). 2021 <h3>Acknowledgements:</h3> NIL. <h3>Disclosure of Interests</h3> None Declared.